WHAT IS A TRUE MORTALITY FOR A RELEASED SALMON?

WHAT IS A TRUE MORTALITY FOR A RELEASED SALMON?

Back to Grays Harbor and the perception that the QIN and
WDF&W do not get along. In communications obtained in Public Document
Request ( PDR's ) it is very clear that
staff from both work together rather well at the technical and preseason
forecast level. In fact I would say compared to years back they have learned to
accommodate each other's views reasonably well. Now as to harvest I cannot say so
as harvest negotiations lack similar documentation as preseason documentation.
Folks will have to draw their own conclusions.

Below is a e mail thread revolving around the Non Treaty
Commercial Net release mortality developed early this year. I will highlight
the portion that I find so interesting. The highlighted portion are QIN
thoughts about release mortalities and in particular WDF&W's resistance to
address the difference in survival of male & female. The QIN thoughts on
female fish pretty much reflect what Chehalis brood stockers encountered with
Chinook. This is important to Rec's as we do need true mortalities for C&R
fisheries and the Commercials are asking that Rec mortality rates be reviewed also.

The thing about mortalities is that it is all about
location & timing. You get all over salmon in midst of transition from
marine to fresh water and nothing good comes from it. The best guidance I was
ever given was for Grays Harbor & Willapa terminal fisheries ( marine
/ tidal / fresh ) was this. Front of the bay fresh out of the
ocean scales not set, low risk. Scales
set coloring up in tidal / marine and in transition is high risk in particular
females. Slimed up in river is low risk and the risk decreases the closer one
gets to the spawning reaches. In fact by the time salmon hit the hatchery ( or
spawning grounds ) they are extremely durable and able to take substantial
handling.

As
I do not edit e mail threads ( other than a private e mail addresses ) the
formatting is a bit off but one can follow the thread so here you go:

Attached is the most up to date version of the Grays
Harbor Planning Model.
We haven't discussed schedules at this time. We've been worked for find
and
correct computation and cell reference error. We appreciate any input you
provide.

I will make sure that your comments of the net release mortality issues are
sent forward.

Is there a planning model for GH that you could provide me to review and
offer QIN proposed changes.

Also on the commercial net release mortality that the Mobrand
group is
working, Steve suggested I should relay our technical information or issues
through you.

I would propose that the wild Coho brood stocking information from 1986 on
for the Hoh River is probably available through Roger Mosely.

The main point of this was that Roger and we found out
that female Coho
taken from the lower Hoh and earlier in the season did not survive well at
all.

I think the lower and earlier ones all died, even though a good number
looked alive and well right up to before their eggs were to mature.

When checking them up to that time at a certain point we would find them
dead and their eggs having not separate from the skeins. Males seemed to
do
fine.

Therefore I would recommend that any release mortality be assessed from the
female survival perspective. Coastal wild escapement estimates are based
on
the number of reeds dug by females.

Any time/area situation in the lower freshwater area that had a similar
impact on female salmon, may render an overall survival rate of 50%, which
would be meaningless as far as achievingescapement objectives. One of the presenters in Olympia before the
Mobrand group also cited their similar experiences brood stocking for what I
believe was the Wishkah group.

I have a question. Do you know the origin of the estimated Humptulips
hatchery stray estimate? In the GH coho forecast model in the run
reconstruction tab within the column labelled "Humptulips Hatchery
Strays"
(column AQ) there is a comment that says "0.8 is applied to total
escapement
est. for Humptulips, this calculation assumes that 20% of fish on spawning
grounds are of hatchery origin. Cannot calculate w/o spawner surv.
Data" .
First, this column multiplies the Humptulips escapement estimate by 0.8.
This produce is then used in the total HATCHERY escapement. Seems that
multiplying by 0.8 is assuming that 80% of the spawners are hatchery origin.
I recall a discussion with Kirt about some CWT analysis that determined the
stray rate. Do you have any recollection? I'm trying to update all
documentation associated with forecasts.